Hi

I'm new to the forum so maybe I 'm doing something wrong. I have posted a problem I 'm having with my 2003 Monte Carlo (charging problem) and recieved no answers. I have reviewed every theard I can find and while the problem has appeared several times there are suggestions on how to fix the problem but no one has written back if any of them work. My problem is that the battery light will come on and the amp gage go all the way down even though the car is charging. (14 volts at battery) the car had a few other electrical problems that were cured by cleaning grounds and terninals. I have had the battery and alternater checked. I have read suggestions like try the bcm or ignition switch but never a post that this has fixed the problem. Parts are to expensive to shotgun the problem. (maybe the car haha)
Thanks for any help

 

Voltage alone is tricky and can make it hard to diagnose electrical. Turn all loads on (high beams, high blower, defroster, wipers, etc.) and see what the voltage stabilizes at. you would be better to clamp the alt wire though and see what it is doing.


Example as to why you don't rely solely on voltage reading. Had a 2008 Impala in with rear defroster inop. Unhooked the wires, 12 volts, what the heck. Hook them back up, 0.00 volts. Grab a test light and sure enough it doesn't light. Come to find out the wire in the kick panel was melted. There was enough continuity to give the meter a reading but not to do anything else.

 

Think of voltage as a water pipe. The bigger the voltage, the larger the amount of water can mover through it. If you think of amperage as the water, well, just because the pipe is big, doesn't mean the pipe will be filled with that water.

My guess is your pipe is large but there is likely a clog further back (that would be the sulfating lead plates in your battery). I can almost guarantee you that your battery is toast; however, there are a few things that can cause this.

How old is your battery?

It sounds like your alternator is working if you can see 14 volts but again, if the windings are intact but there is some that are thin, same volts/amps issue.

 

I recommend haveing your chargeing system checked...

If your chargeing system, shows no issues and is working properly...
I would remove the bulb from the "idiot" light...
Then I would instahl, An after market Amp gauge...

Thus alleviateing your issue and worries over idiot lights and faulty gauge!